Transfers

ABSTRACT

THIS INVENTION RELATES TO TRANSFERS WHICH INCLUDE A CARRIER SHEET HAVING DISPOSED THEREON A RELEASE LAYER, A LACQUER LAYER, AN INK OR DYE LAYER COVERING AN AREA LESS THAN THAT OF THE CARRIER SHEET AND ADAPTED TO BE PROTECTED BY SAID LACQUER LAYER, AND A LAYER FORMED FROM A METAL AND SUPERPOSED ON THE INK OR DYE LAYER.

Jan. 2, 1973 G. c. HURST ETAL 3,708,320

TRANSFERS Filed Oct. 2, 1969 s ,,,.4 H, ,2 51 \l i 13 k\(\\\ I FIG.|

INVENTORS GERALD COVINGTON HURST ALAN BELASCO United States PatentOffice 3,708,320 Patented Jan. 2, 1973 3,708,320 TRANSFERS GeraldCovington Hurst, Coulsdon, and Alan Belasco,

Kenley, England, assignors to George M. Whiley Limited, South Ruislip,Middlesex, England Filed Oct. 2, 1969, Ser. No. 863,143 Claims priority,application Great Britain, Oct. 14, 1968, 48,648/ 68 Int. Cl. B41m 3/12;B44d 1/14 US. Cl. 1173.3 3 Claims ABSTRACT OF THE DISCLOSURE Thisinvention relates to transfers which include a carrier sheet havingdisposed thereon a release layer, a lacquer layer, an ink or dye layercovering an area less than that of the carrier sheet and adapted to beprotected by said lacquer layer, and a layer formed from a metal andsuperposed on the ink or dye layer.

This invention relates to transfers and more particularly, but notexclusively, to heatand/ or pressure-sensitive transfers.

Pre-printed designs, transferable from a carrier by the action of heatand pressure, incorporating only coloured areas, are known. Also knownare hot stamping foils which include a lacquered metal or coloured layerwhich is transferable to a surface by the action of heat so as toreproduce the design of a metal die. These are also used with flatrubber dies to cover the raised part of a moulding. See Modern PlasticsEncyclopedia 1968, pp. 1016- 1019.

Previously, when it has been desired to produce a design, part of whichhas a metallic appearance, it has been necessary to build up the designin a series of layers. The desired effect would thus be achieved byemploying stamping foils of different types in several operations.Obviously, such a process is inefficient. In this connection, it shouldalso be borne in mind that, in practice, it is difficult to apply metalin a vacuum chamber to only a limited part of a surface.

Consequently, it is an object of the present invention to provide atransfer capable of providing in one step a finish for, for example, aplastics, paper or wood surface, similar to the finish obtained by asuccession of hot stampings with both coloured sheets and lacqueredaluminium stamping foils.

According to one aspect of the present invention, there is provided atransfer which includes a carrier sheet having disposed thereon an inkor dye layer covering an area less than that of the carrier sheet, and alayer formed from a metal and superposed on the ink or dye layer, and anadhesive layer applied only to that part of the metal layer where it isintended that the design layer be transferred.

According to another aspect of the present invention, there is provideda method for producing a transfer according to the present invention,which method comprises applying an ink or dye to part, but not all, ofone side of a carrier sheet, and forming by vapour deposition a layer ofmetal on the partially inkor dye-coated side of the carrier sheet, andapplying an adhesive composition to the metal layer only in those partswhere it is intended that the design be transferred.

Aluminium is a particularly suitable metal for the metal layer since alayer of it can be formed easily by known vapour coating techniques.Examples of other metals suitable for the metal layer include gold andantimony, although these are more expensive than aluminium. It will beappreciated of course that any metal which has a desired colour andwhich can be formed into the metal layer can be used.

In one embodiment of the invention, the transfer has, going from oneside of the transfer to the other, a carrier sheet, a release layer, alacquer, an ink or dye layer covering part of the lacquer layer, a metallayer and an adhesive layer. The production of this type of transferwill now be described.

Firstly, a thin carrier sheet, for example one formed from apolyethylene terephthalate film such as the commercially availableMelinex or Mylar polyester film, is coated with a release layer. Melinexis a trademark of Imperial Chemical Industries, and Mylar is a trademarkof El. du Pont de Nemours and Company. Other materials, e.g. nylon 6,may be used provided that they do not give rise to a high vapourpressure which would adversely affect the vacuum metallising operationhereinafter described. The release layer can comprise, for example, aheat softenable Wax-based composition similar to the release layersemployed in the manufacture of stamping foils. It may be composed of awax alone or of a wax and resin mixture. The composition is one whichwill provide a firm adhesion to the carrier sheet whilst cold and whichwill readily release the carrier sheet when warm or hot. Elastomericsubstances such as natural rubber, may be included in the composition toimprove adhesion during handling.

The release layer is next lacquered, either overall, for example bygravure or roller coating, or in part by the use of, for example, a silkscreen or a partly etched gravure. The lacquer composition may be variedconsiderably provided that it is not affected adversely by thesubsequent vacuum metallising process described hereinbelow, is notcompatible with or affected adversely by the release layer, and adhereswell to the metal, for example aluminium, layer. The following materialsare examples of materials which have been used in preparing lacquers:nitrocellulose, methyl methacrylate and copolymers thereof, chlorinatedrubbers, phenolic resins, non-drying alkyd resins, ureaformaldehyderesins, and epoxy resins.

After lacquering, that part of the design of the transfer which is to becoloured is printed in reverse, for example, by gravure, flexographic orsilk screening. Examples of suitable ink for use in the printing includesolutions of resins capable of binding pigments, and containing enoughplasticising material to provide cohesion. In practice, the pigmentsWill have been dispersed in the resin by conventional means. It isconvenient to incorporate a register mark into the design to facilitatethe subsequent application of the adhesive coat as Well as the automaticapplication of the completed transfer.

Generally, at this stage it is necessary to thoroughly dry the materialin order to remove moisture and solvent. The material is then subjectedto a high vacuum and coated with the metal layer, for example aluminium.

Finally, adhesive is applied to the metal layer so that it covers eachintended transfer area entirely but does not cover the space between theareas. The adhesive used must be capable of slight softening when heatedand must form a firm bond with the material to which the design is to beapplied. It will be appreciated that different adhesives are chosen fordifferent surfaces, and it has been found advantageous to pigment theadhesive in order to provide a relatively thick layer without permittingflow from the areas to which it has been applied under the transferconditions of heat and pressure. Any dispersed solid extender pigment orfiller may replace the pigment without altering the characteristics ofthe system. Silk screen application has been found to be the mostsatisfactory method of obtaining good adhesive layers.

When the transfer is placed against the surface to which the design isto be applied and a heated press, for example a silicone rubber orlaminated metal-rubber die, is pressed firmly against the transfer, therelease layer melts and that part of the design which has been coveredby the adhesive transfers to the article to be marked. The areas coatedby lacquer alone give the appearance of a bright metal, for example goldor silver or a colour depending on the lacquer, and the remaining areasare the colour of the ink used, providing the lacquer is clear. If avery deeply coloured lacquer is used, it is generally applied to onlypart of the design, whereas a light or clear lacquer may be appliedoverall, in which case it provides overall resistance against abrasionto the design. Alternatively, the deeply coloured lacquer may be appliedas an overall lacquer after the pigmented part of the design has beenprinted.

In another embodiment of the invention, the transfer is similar to thatdescribed in the first mentioned embodiment except that the lacquerlayer and release layer can be combined so as to produce a singlelacquer layer having the desired release properties with regard to thecarrier sheet. Such a lacquer can be prepared from, for example, asolution of polymethyl methacrylate.

Mention has already been made of an adhesive which is capable of slightsoftening on heating but which forms a firm bond with the surface towhich the design is to be applied. However, other types of adhesives canalso be used-in the transfer of the invention, for example the typewhich is non-tacky in its ordinary state but becomes permanentlyadhesive when it is in the presence of a particular compound or uponheating. An example of the first type is one which becomes tacky whenwater is added to it and of the second type is one which is preparedfrom a copolymer of ethyl hexyl acrylate and a dispersed solidplasticiser such as cyclohexyl phthalate.

For a better understanding of the present invention, and to show how thesame can be carried into effect, reference will now be made, by way ofexample, to the accompanying drawing, in which:

FIG. 1 is a cross-section through a transfer; and

FIG. 2 is a plan view of the design of the transfer of FIG. 1 applied toan object.

Referring firstly to FIG. 1, there is shown a transfer having a carriersheet 1 adjacent a release layer 2 which in turn is adjacent a lacquerlayer 3 on which has been deposited a design in ink 4. The ink 4 iscovered by, and the spaces between the ink design 4 filled with, a metallayer 5 which has been formed by a metal vapour deposition method. Onthe metal layer is an adhesive layer 6 which covers only that part ofthe design which is to be transferred in use.

In FIG. 2 there is shown a design of the type which can be produced byapplying the transfer of FIG. 1 to an article 7. The design consists ofa coloured hollow rectangle 8 inside which is another rectangle 10, eachrectangle being the colour of the ink 4, which can be different for thedifferent rectangles. The area 9 is the colour of the metal layer 5 ifthe lacquer of the layer 3 is clear. Otherwise, the colour of the area 9will depend on the combination of the colour of the lacquer 3 and thatof the metal layer 5.

The invention will now be illustrated by the following examples.

EXAMPLE 1 about 1 gm. per square yard (of non-volatile matter)consisting of a 25% by weight solution of equal parts of ImperialChemical Industries nitrocellulose DHX 8/13 and a methyl butylmethacrylate copolymer, dissolved in a mixture of equal parts by weightof methyl cyclohexanone and methyl ethyl ketone.

A design was then applied to the lacquer layer in black and blue inks.

The resulting product was dried and then vapour-coated with sufiicientaluminium to provide a bright continuous surface and cooled. To thealuminium was then applied an adhesive suitable for adhesion to paper,board or thermosetting plastics.

In the cases when the transfer was to be applied to polystyrene orcellulose acetate surfaces, a suitable adhesive was used.

The transfers were easy to prepare and the designs were found to beeasily transferable.

EXAMPLE 2 A roll of biaxially oriented nylon 6 film, 25 microns thick,was coated on a conventional roller coating machine, with a releasecomposition which consisted of 2 g. of a partly saponified ester wax(melting point -104 C.) and 0.05 g. of crepe rubber, dissolved in onelitre of trichloroethylene. On drying, approximately 0.1 g. of releasecomposition remained on each square metre of the nylon film. A clearlacquer having the following composition was then printed onto thecarrier on a gravure machine so that there was about 1 g. of lacquer persquare metre of dry material:

Chlorinated rubber g 100 Chlorinated parafiin wax g 50 Xylene c 300 Thechlorinated rubber was that sold by Imperial Chemical Industries Limitedunder the registered trademark Alloprene R10 and the chlorinatedparaifin was one obtained from the same supplier and known as Cerechlor70.

A yellow and green design was applied in two stages, by silk screening,with inks which were ground dispersions of the following compositions:

The vinyl toluene used was one supplied by Messrs. Hubron Sales Limited,known as Pliolite VT.

The coated and printed nylon film was then well dried and a layer ofaluminium was applied to it by vapour coating in the usual way.

Finally the whole area of the design, which it is intended to transfer,was coated, by silk screening, with a ground dispersion of pigment andresinous adhesive. The coating exceeded the area of the design by ,5 allround.

The carriers and transfers were reeled and cut longitudinally. Registermarks were included in the design and the transfer was tested onautomatic machinery.

It was found that the entire mark transferred well when pressed out onto polystyrene or methyl methacrylate surfaces, or on to coated fabricsand painted materials, using a heated silicon rubber pad, maintained ata surface temperature of about C. at a contact time of 2 seconds. Thealuminium layer gave a bright silver appearance to the design where itws not covered by the yellow or green ink portions. The design wassurrounded by ,1 inch of bright aluminium where the adhesive overlappedthe coloured ink. In a modification in which the adhesive coat wasapplied to the whole sheet, and not just to the design area, a similarresult was obtained but it was necessary to shape the heatable rubberpad carefully (so as to restrict the area of transfer) and to ensurethat the transfer design was registered very accurately with the articleto be marked and the shaped rubber die.

EXAMPLE 3 A 100 gauge polyester carrier sheet, originally in roll form,was coated with a release layer as described in Example 1, thenlacquered with a solution having the following composition:

G. Nitrocellulose DHX 3/5 (70%) 100 100% non-drying oil modified alkydresin 50 Cyclohexanone 200 Isopropanol 50 Orange dyestuff The figures3/5 indicate the time range in seconds for a stainless steel ball of cm.diameter to fall 50 cm. through a solution at 20 C. formed by dissolving40 g. of the dry nitrocellulose in 100 ml. of 95% acetone (5% water).

The alkyd resin was one supplied by Imperial Chemical IndustriesLimited, known as Paralac 685.

A design in inks of several different colours formulated similarly tothose described in Example 2 was applied in the same way. The resultingmaterial, when well dried, was metallised with aluminum and an adhesivecoat similar to that described in Example 2 printed on to the area ofthe design. This gave a transfer of much the same quality as the earlierexamples, with the part of the aluminium not covered by ink, appearingas a pale gold, bright layer.

EXAMPLE 4 The lacquer and release coat described in Example 2 wereapplied to a polyester carrier sheet of 100 gauge. Then a designprepared from the same inks as described in Example 2 was applied to thelacquer layer. After drying, this was coated, by the usual vapourmetallising technique, with gold from 23 carat gold wire to the extentof about 0.07 g. per square metre. After application of the adhesivecoat, and upon transference, a bright and attractive transfer wasobtained which had the additional advantage of great resistance tocorrosion.

What is claimed is:

1. A transfer of the type consisting of a carrier sheet having a coatingof release material on one surface thereof, a lacquer layer disposed onsaid release coating, an inkor dye design only partially covering oneside of the lacquer layer and adapted to be protected by said lacquerlayer, a layer formed from a metal deposited under vacuum and coveringall of said design and covering all areas of said lacquer layer otherthan the areas of said lacquer layer having said design thereon, and anadhesive layer applied to only part of the metal layer, namely to thatpart where it is intended that the design be transferred.

2. A transfer of the type consisting of a polyester carrier sheet, arelease layer formed of a heat softenable wax disposed on one side ofthe carrier sheet, a protective lacquer layer formed of nitrocellulose,a polymer of methacrylate, a copolymer of methacrylate, a chlorinatedrubber, a phenolic resin, a non-drying alkyd resin, a ureaformaldehyderesin, or an epoxy resin disposed on the release layer on the side ofsaid release layer remote from the carrier sheet, an ink or dye designdisposed on the lacquer layer on the side of the lacquer layer remotefrom the carrier sheet, said design having an area less than that of thelacquer layer and only partially covering the area of said lacquerlayer, a metal layer formed from aluminum, gold or antimony depositedunder vacuum and covering all of the design and covering all areas ofsaid lacquer layer other than the areas of said lacquer layer havingsaid design thereon, and an adhesive layer formed of a heat softenablematerial disposed on the metal layer on the side of the metal layerremote from the carrier sheet and on only part of the metal layer,namely on that part where it is intended that the design be transferred.

3. A transfer of the type consisting of a polyester carrier sheet, acombined protective lacquer-release layer formed ofpolymethylmethacrylate disposed on the carrier sheet on one sidethereof, an ink or dye design disposed on the lacquer-release layer onthe side of the lacquer-release layer remote from the carrier sheet,said design only partially covering the areas of said lacquer-releaselayer, a metal layer formed from aluminum, gold or antimony depositedunder vacuum and entirely covering the design on the side of the designremote from the carrier sheet, the metal layer covering the entire areaof the lacquer-release layer other than the area of said lacquer-releastlayer having the design thereon, and an adhesive layer formed of a heatsoftenable material disposed on the metal layer on the side of the metallayer remote from the carrier sheet and on only part of the metal layer,namely on that part where it is intended that the design be transferred.

References Cited UNITED STATES PATENTS 2,017,367 10/1935 Kurz 1173.32,099,641 11/1937 Bach et al 1173.3 X 2,159,693 5/1939 Gaylord 1173.42,190,405 2/ 1940 Humphner 1173.4 X 2,351,933 6/1944 Decker et al117-3.1 X 2,684,918 7/1954 Oughton 1173.3 2,746,877 5/ 1956 Matthes117-3.4 X 2,758,035 8/ 1956 Matthes l17-3.6 2,941,916 6/ 1960 Akkeron1173.6 X 3,235,395 2/1966 Scharf 1173.4 X 3,463,651 8/1969 Warsager1173.3 1,882,593 10/1932 Hentschel 1173.3 X

FOREIGN PATENTS 816,022 6/ 1969 Canada 1l73.l

WILLIAM D. MARTIN, Primary Examiner H. J. GWINNELL, Assistant ExaminerUS. Cl. X.R. 117-45

